数值堆热工流体程序CVR-PACA验证及典型应用

谱元方法是一种高精度的数值计算方法，采用该方法开发了数值堆高精度热工水力并行CFD计算程序CVR-PACA。应用CVR-PACA对单棒光棒通道湍流流场、3×3光棒棒束湍流流场、Matis-H压水堆棒束通道基准题、19棒带绕丝组件通道湍流流场进行了仿真计算。通过与实验测量值对比，研究定量验证了大涡模拟(LES)模型及非稳态雷诺时均(URANS)模型对各类棒束通道流场预测的准确性。算例在建模过程中采用网格分裂技术实现了复杂几何的纯六面体网格划分，用于支撑谱元方法计算。研究较为全面地积累了高精度谱元方法模拟流场流动及换热的建模经验，获取了各类棒束通道内丰富的流动和换热细节，获得的建模经验能更加精准有力地指导相关设计的优化改进。

Validation and Typical Application of Thermal-hydraulic Code Analysis in Numerical Reactor with CVR-PACA Code

Spectral element method (SEM) is a high-order numerical method. A high-precision parallel CFD code CVR-PACA for thermal-hydraulic analysis of numerical reactor was developed by using this method. In this paper, CVR-PACA was employed to model and predict turbulent flow in single bare rod, 3×3 bare rod bundle, Matis-H benchmark and 19 wire-wrapped rod bundle, aiming to validate the predicting capability of large eddy simulation (LES) model and unsteady Reynolds-averaged (URANS) model within the typical applications of thermal-hydraulic analysis in fuel assembly of reactor core. Spatial discretization for complicated geometries was also achieved with full-hexahedral mesh using mesh splitting method. Much more modeling experience of high-precision CFD code CVR-PACA were accumulated during the calculation processes and abundant flow and heat transfer details in various rod bundle channels were obtained, while result from CVR-PACA could provide more thermal-hydraulic details for design optimization.